Simulation of laser-induced molecular rotation; Application to laser isotope separation of HO and TO

Namba, Tomotaro  ; Kumagai, Yuta   

Because isotopes have similar chemical properties, isotope separation is more difficult than elemental separation. Laser isotope separation (LIS) provides high efficiency in a single-stage process. However, LIS is molecule-specific and requires tunable narrowband laser sources. An isotope-selective separation by nonresonant laser-induced molecular rotation was developed to overcome the limitation of laser sources. For linear molecules, it is efficient to irradiate iterative laser pulses timed to a molecular rotational period. On the other hand, asymmetric-top molecules, such as HO, do not have a clear rotation period. We numerically simulate laser-induced molecular rotation of HO and TO in the gas phase and determine appropriate pulse parameters, including polarization conditions, intensity, and timing of irradiation.